CDN-239: The First Data Gate — Proxy fit, taxonomy census, and branch assessment from a twelve-cluster sample

CDN-239 passes the first data-facing gate of the GCFT dual register. A 12-cluster sample from published weak-lensing masses and X-ray gas fractions is assembled, the sigmoid κ-proxy is fitted (loss=0.039, mean |Δκ|=0.039), and all four taxonomy classes {P,F,S,E} are populated for the first time. The data-driven saturation tolerance is ε_sat=0.09. Both branches score as Strong; neither dominates. CDN-240 inherits both tracks.